In vitro measurement of the ultraviolet protection factor of apparel textiles

The effect that ultraviolet radiation has on skin is a topic of growing interest. Textiles protect against ultraviolet radiation, but the protection provided is often not sufficient. The aim of the present review article is to clarify some basic concepts regarding the in vitro measurement of the protection factor against ultraviolet radiation provided by apparel textiles, paying special attention to the factors that are taken into account to measure it. The conditions for correct and reproducible measurement are described. The peculiarities of current standards and the details for their correct interpretation are also explained, including sample preparation and statistical calculations to determine measurement error and the adjustment of the results.